This application claims the benefit of Korean Application No. 2001-23341, filed Apr. 30, 2001, in the Korean Industrial Property Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a personal display system, and more particularly, to a wearable display system capable of displaying a display signal transmitted through a magnifying optical device, such as an eyeglass-type or goggle-type optical device, at a location near the eye of a user.
2. Description of the Related Art
Conventional optical display systems generally known as head (helmet) mounted display (HMD) systems have been designed for users to see video signals magnified via an eyeglass-type, goggle-type or helmet-type wearable device. These systems may be used in the military, medicine, or for personal entertainment. This personal display system allows users to receive video information while moving from place to place.
FIG. 1 shows an example of the appearance of a conventional HMD. Referring to FIG. 1, the HMD is made of eyeglasses 100 and an image-driving unit 110 that is attached at the center of the eyeglasses 100. Because of the image-driving unit 110, the HMD is bulky, heavy and not elegant. The image-driving unit 110 is large and heavy because many optical elements are included in the unit.
FIG. 2 shows the structure of a conventional HMD. In FIG. 2, the HMD includes an image-driving unit 200, a display panel 210 and an optical system 220. The image-driving unit 200 stores an image signal received from external sources such as a personal computer or video device (not shown), processes the received signal and displays the signal on the display panel 210, such as a liquid crystal display (LCD) panel. The optical system 220 makes the image signal displayed on the display panel 210 appear as a virtual image in the eye of a user via an enlargement optical system. The HMD may further include devices used to wear the HMD or a cable for receiving the image signals from the external source.
FIG. 3 shows the general structure of the optical system 220 of the conventional HMD of FIG. 2. A conventional optical system includes a collimating lens 300, an X prism 310, focusing lenses 320, fold mirrors 330 and ocular lenses (or magnifying lenses) 340. The collimating lens 300 collimates and propagates light (an image signal) emitted from the display panel or the like. The X prism 310 redirects the light received from the collimating lens 300 in both the right and left directions. The focusing lenses 320 are separately placed on the right and left sides of the X prism 310 so that collimated light passing through the X prism 310 is focused. The fold mirrors 330 change the direction of incident light so that the light focused by the focusing lenses 320 travels toward the eyes of a user. The ocular lenses (or magnifying lenses) 340 allow small image signals passing through the above-described optical elements to appear in the eyes of the user. At this time, if an image signal transmitted through the ocular lenses 340 has color, lenses for removing a chromatic aberration must be used as the ocular lenses 340.
In the conventional HMD, the optical system 220 employs several optical elements to meet precise design specifications. For this reason, it is difficult to manufacture the general wearable display system because much effort, expense and time are required. Even if the lenses and elements are designed precisely, difficulty in aligning the lenses and devices may occur. Furthermore, the conventional optical system is bulky and heavy due to the use of a plurality of optical devices, thus, it is inconvenient for a person to wear the HMD.
Accordingly, it is an object of the present invention to provide a wearable display system that is simple to manufacture using a minimum number of optical devices.
Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
The foregoing and other objects of the present invention are achieved by providing a wearable display system including a display panel to output a signal processed in a predetermined way; a grating to diffract the signal output from the display panel; a waveguide to guide a propagation of the signal diffracted by the grating, the waveguide including first and second substrates; and a magnifying lens to magnify the signal propagating through the waveguide.
The foregoing and other objects of the present invention are also achieved by providing a method of manufacturing a wearable display system that includes a display panel to display a signal processed in a predetermined way, the method including forming a first optical device on a first substrate, the first optical device to transmit the signal displayed by the display panel into the first substrate at a predetermined total internal reflection angle; forming a second optical device on a second substrate, the signal being transmitted into the second substrate at the total internal reflection angle, the second optical device to receive the signal from the second substrate and output the received signal; and combining the first and second substrates.
The foregoing and other objects of the present invention are also achieved by providing a wearable display system including at least one display panel to display a signal processed in a predetermined way; at least one grating to diffract the signal displayed by the display panel; a waveguide to guide a propagation of the signal diffracted by the grating, the waveguide including first and second substrates; and at least one magnifying lens to magnify the signal propagating through the waveguide.